An Analysis of Spacing Dependencies in Perpendicular Magnetic Recording

The dependence of the reproduced output on the head-medium spacing in perpendicular magnetic recording systems has been analyzed by computer simulation and compared with equivalent effects in longitudinal magnetic recording. In the recording process, the spacing loss coefficient shows little dependence on the bit length, because the recording field gradient of a single pole head is not significantly changed by a change in spacing. On the other hand, the spacing loss coefficients in the reproduction process change and become larger as the bit length becomes longer. This is because the read sensitivity function of a single pole head is changed by the strength of the head-medium magnetic coupling, which depends on the head-medium spacing.